Well packer apparatus

ABSTRACT

An illustrative embodiment of the present invention in retrievable well packers includes a body member carrying settable packing means adapted to sealingly engage a well casing wall, normally retracted slip means, and expander means movable downwardly relative to said slip means for shifting said slip means outwardly into gripping contact with a well casing wall, and hydraulic means above said packing means and coupled in force transmitting relationship thereto, said hydraulic means being responsive to greater fluid pressure in the well bore below said packing means than above said packing means for applying setting force to said packing means and said expander means to retain said packing means and said slip means in set positions.

United States Patent [72] inventor William Berryman 3,387,658 6/1968Lebourg l66/129X Hous 3,392,783 7/1968 Reed 166/129X [21] Appl. No.781,031 3,399,729 9/1968 McGill 166/120 [22] Filed Dec. 4,1968 3,409,08511/1968 Oliver 166/134 [45] P n J 5,1971 3,416,608 12/1968 Crow et a1.166/134X 1 Assignee Schlumberger Twhnology Coqmrafion 3,426,846 2/1969Young 166/120X i I New York Pririzary Examiner-David H Brown acorporation Texas Attorneys-Ernest R. Archarnbeau, Jr., William J.Beard,

David L. Moseley, Edward M. Roney, William R. Sherman s4 WELL PACKERAPPARATUS and Stewart Moore 14 Claims, 8 Drawing Figs. [52] US. 6/ABSTRACT: An illustrative embodiment of the present inven- /129 tion inretrievable well packers includes a body member carry- [51 Int. Cl.E211) 33/129, ing seflable packing means adapted to sealingly engage awell Ezlb 23/06 casing wall, normally retracted slip means, "andexpander [50] Field ofsemch 166/120, means movable dow wardly relativeto said slip means for 175/230 shifting said slip means outwardly intogripping contact with a well casing wall, and hydraulic means above saidpacking [56] References Cmd means and coupled in force transmittingrelationship thereto, UNITED ST TES AT said hydraulic means beingresponsive to greater fluid pres- 3,088,532 /1963 Kellner 175/230 surein the well bore below said packing means than above 3,277,965 /1966G'rimmer.... 166/ 120 said packing means for applying setting force tosaid packing 3,338,308 8/1967 Elliston et a1. 166/120 means and saidexpander means to retain said packing means 9 3,356,142 12/1967 Crow eta1. 166/118 q and slip means in set positions.

97 v C a: I N 39 "warm 11.1- a

PATENIEDJAHSIQYI 3552.489

SHEETlUFS ATTORNEY W////am 0. Berry/nan WELL PACKER APPARATUS Thisinvention relates generally to well packers used in well bores, and morespecifically, to a production packer which can be easily manipulated inset position in a well bore, and which can be anchored in packed-offcondition against movement in either direction in the well bore.

In installing aproduction string in a well, a packer is usually loweredon a pipe string and set above'the producing horizon in order to isolateit from adjacent zones in the well. The pipe string is then hung in aChristmas tree which is installed at the surface. In installing theChristmas tree, a certain amount of manipulation of the pipe string maybe necessary, yet the exact location of the packer may be quitecritical. Thus, it is desirable to provide a packer which can beprecisely located at a predetermined setting position, and which isconstructed and arranged such that the pipe string can be furthermanipulated at the surface during installation of the Christmas treewithout disturbingthe setting position of the packer.

Fluid pressure may be imposed on a production packer from above orbelow. For example, it may be desirable to treat or,stimulate aproducing zone before it is put on production and without removing thepipe string. In this case, pressure may be imposed from below. Moreover,subsequent remedial work may be anticipated. During actual production,it is possible that the pressure in the annulus above the packer may begreater than the pressure below it. In any event, such pressures licallyoperated by pressure from below. Although this arrangement may be quitesatisfactory, the use of separate anchor assemblies provides forconsiderable complexity of the tool, increasing the cost as well as thechances of malfunctions. In some instances, such packers aredifficultto' retrieve.

It is accordingly an object of the present invention to provide a newand improved retrievable well packer apparatus which can be set on apipe string at a precise location in a well bore, and which permitsfurther manipulation of the pipe string at the surface withoutdisturbing the setting location of the packer.

Another object of the present invention is to provide a new and irnproved production packer having only a single slip and expandercombination for preventing movement due to pressure in eitherlongitudinal direction in a well bore.

These and other objects are attained in accordance with the concepts ofthe present invention by a well packer apparatus including a bodymember-adapted for connection to a pipe string extending'upwardly to theearths surface. Normally retracted slip means are arranged to beexpanded outwardly into gripping contact with a well. casing wall by adownwardly movable expander in order to anchor against downwardmovement. A settable packing structure is carried by the body member andis arranged to be expanded outwardly into sealing engagement with a wellcasing wall when subject to longitudinal compressive force. A series ofpiston and cylinder combinations are located above, and in coupledrelationship to, said packing structure and are responsive to greaterfluid pressure in the well bore below said packing structure than abovesaid packing structure to provide downward force on the packingstructure, thus increasing the compression on the packing as well asforcing the expander downwardly relative to the slip means in order toretain the slip means in gripping contact with the well casing wall.Means are also provided for locking the slip means and packing structurein expanded positions, while enabling a significant extent oflongitudinal movement of the body member relative thereto, so that thepipe string can be manipulated as desired at the surface withoutdisturbing the set condition or location of the packing and slips.

The present invention has other objects and advantages which will becomemore clearly apparent in connection with the following detaileddescription of a preferred embodiment taken in conjunction with theappended drawings in which:

FIG. 1 is a longitudinal view of a production packer accord ing to thepresent invention being lowered into a cased well bore on a pipe string;

FIGS. 2A and 2B are longitudinal sectional views, with portions in sideelevation, of the well packer of the present invention with parts inrunning-in positions, FIG. 2B forming a lower continuation of FIG. 2A;

FIG. 3 is a cross section taken on line 3-3 of FIG. 28;

FIG. 4 is a schematic plan view of a coupling slot and lugconfiguration;

FIG. 5 is a cross section taken on line 55 of FIG. 2A; and

FIGS. 6A and 6B are views similar to FIGS. 2A and 2B but with parts intheir relative positions when set in the well casing.

Referring initially to FIG. 1, a well bore B transverses earthformations and is lined with a casing C which is nonnally ce mented inplace. A well packer 10 in accordance with the principles of the presentinvention is lowered into the well casing C on a pipe string P which,after the packer 10 is set, will channel produced fluids to the surface.The well packer 10 includes a central body member or mandrel 11 whichcarries a packing assembly 12 adapted to be expanded to pack off theannulus between the pipe string P and the well casing C. A set ofnormally retracted slips 13 are mounted on the upper end of a cagemember 14 which has drag blocks 15 frictionally engaging the wellcasing. The slips 13 are adapted to be shifted outwardly into grippingcontact with the well casing C by downwardly movable expander 16.

A pressure responsive assembly including a plurality of piston andcylinder combinations 17, 18 and 19 is mounted above the packingassembly 12 as will be described in detail hereafter. A fluid bypasspassage to aid in lowering the packer to setting depth is providedbetween the packing assembly 12 and the body member 11, and the bypasspassage is arranged to be closed off at its upper end by a valve head 20carried near the upper end of the body member 11. Moreover, a forcebalancing system is provided to aid in maintaining the valve head 20 inclosed position when fluid pressure is imposed on the packer from below,the system including a locking assembly 21 which is cooperable with theupper end of the pressure assembly to enable the pressure in the wellbore below the tool to act downwardly on a balance piston to bedescribed hereinafter. In the drawings, the body member 11 is brokenabove the pressure responsive assembly to indicate that the body membercan be quite long so as to enable considerable relative longitudinalmovement between it and the packing assembly 12.

Turning now to FIGS. 2A and 2B, the body member 11 has a central bore 24and extends throughout the length of the tool. The body member has athreaded box 25 at its upper end adapted for connection to therunning-in string of tubing or drill pipe P, and a threaded pin 26 atitslower end adapted for connection to a string of pipe or to anotherwell tool. An elongated sleeve member 27 is mounted on the body member11,

the inner wall surface of the sleeve member being spaced laterally awayfrom the outer wall surface of the body member over a considerableportion of its length to provide an annular fluid bypass passageway 28opening at its upper end to the well bore as shown in FIG. 2A. Thepassageway 28 is arranged to be closed off by the annular valve head 20which is threadedly secured to an upper portion of the body member 11,the valve head carrying a seal ring 29 which can seal against aninternal valve seat 50 on the sleeve member 27 when the parts aretelescoped together.

- The packing assembly 12 is mounted around the compression sleeveintermediate its ends, and includes a plurality of elastomeric packingrings 31 separated by annular spacer rings. The packing rings 31 areadapted to be expanded into sealing engagement with the wall of the wellcasing when subjected to longitudinal compression force. The upper oneof the packing rings 31 is engaged by an upper annular abutment 32 whichis slidable downwardly relative to the sleeve member 27, and the lowerone of the packing rings 31 is engaged by a lower annular abutment 33which is slidable upwardly relative to the sleeve member. The lowerabutment 33 can be threadedly attached to the upper end of the expander16 which is constituted by a sleeve portion 34 and a cone or wedgeportion 35 having downwardly and inwardly inclined outer surfaces 39.Downward movement of the lower abutment 33 relative to the sleeve member27 is limited by engagement with an annular shoulder 36 on the sleevemember. Several flow ports 37 are formed through the wall of the sleevemember 27 below the shoulder 36 which, together with several flow ports38 through the wall of the sleeve portion 34, serve to communicate thebypass passageway 28 with the well bore below the packing assembly 12.

The cage member 14 is carried near the lower end portion of the sleevemember 27, the cage member being provided with a plurality ofcircumferentially spaced, radially directed recesses 41, each of whichreceives a drag block 15. Each drag block is urged outwardly intofrictional engagement with the well casing wall by coil springs 42. Aplurality of slip elements 13 are movably mounted on the upper end ofthe cage member 14 and have wicker-s or teeth 43 formed on their outerperipheries, an inner surface 44 on each slip element incliningdownwardly and inwardly toward the sleeve member 27. The surfaces 44 arecooperable with the inclined surfaces 39 on the expander cone 35 tocause outward shifting of the slip elements 13 into gripping engagementwith the well casing wall. Each slip element 13 is attached to the cagemember 14 by-a rein 45 on the like having one end pivotally connected toa slip element by a pin 46, and the other end being pivotally connectedto the cage member 14 by a pin 47 engaging in a lost-motion slot toenable the inward and outward movement of the respective slip elementsrelative to the cage member with the lower end surface of each slipelement being supported by the cage member. Each slip element 13 isnormally biased inwardly in retracted position by a spring 48.

A control housing 50 is threadedly attached to the lower end of the cagemember 14, the housing initially extending downwardly below the lowerend of the sleeve member 27. An annular, split clutch ring 51 isreceived within the housing, the ring having buttress type threads 52 onits outer periphery formed to face downwardly and cooperable withupwardly facing buttress type threads 53 formed on the inner wall of thehousing 50. Due to its split construction, the clutch ring 51 isradially expansible a'nd contractible. The lower end portion 54 of thesleeve member 27 has a plurality, for example four, windows 56 in thewall thereof as shown in FIGS. 28 and 3, each window receiving alaterally movable latch element57 having teeth 58 formed on its outerperiphery. The clutch ring 51 has companion teeth 59 formed on its innerperiphery which are engageable with the latch element threads 58 whenthe latter is telescoped within the former. When the parts of the packerare in their running-in position as shown in FIGS. 2A and 2B, the latchelements 57 are positioned adjacent a reduced diameter portion 60 of thebody member 11, the reduced diameter portion enabling inward movement ofthe latch elements. However, when the body member 11 is moved downwardlyrelative to the sleeve member 27, an enlarged portion 61 is providedwith a backup surface 62 which, when positioned behind the latchelements 57, shifts them outwardly somewhat and prevents their inwardmovement. The coaction of the outer teeth 52 on the clutch ring 51 withthe inner teeth 53 on the housing 50 is such that when the threads 58 onthe latch elements 57 are engaged with the threads 59 on the clutchring51, and the backup surface 62 is positioned behind the latch elements57, any upward movement of the clutch ring 51 relative to the housing 50will cause the threads 58 and 59 to be cainmcd inwardly into moreforceful engagementwith one another, thereby holding the sleeve member27 in a lower position relative to the cage member l4.

In order to properly position the parts during lowering into the wellbore, the housing 50 is provided with an inwardly extending control lug64 which is cooperable with a jay-slot 65 formed in an outer peripheralportion at the lower end of the body member 11. The slot construction,shown in H6. 4, has a closed end channel 66 in which the lug 64 engagesduring downward shifting in the well bore, and which is connected by aninclined channel 67 with an open ended channel 68. Thus, as long as thelug 64 is in the closed end channel 66 as shown in FIG. 2B, the cagemember 14 cannot move upwardly relative to the body member 11 and theslip elements 13 are held in spaced relation to the expander 16.However, by raising the body member 11 slightly, and then torquing tothe right while lowering it, the lug 64 can be disengaged from thejay-slot 65 to enable downward movement of the body member 11 relativeto the cage member 14. The lower end of the sleeve member 27 restsagainst an upwardly facing shoulder 69 on the body member 11, and thelower abutment 33 rests against the upwardly facing shoulder 36 on thesleeve member 27 so that the expander cone 35 and the slip elements 13are held away from one another as long as the lug 64 is engaged withinthe closed end channel 66 of the jay-slot. Further, an upwardly facingshoulder 70 on the sleeve member 27 can engage a downwardly facingshoulder 71 on the cage member 14 to limit upward movement of the sleevemember relative to the cage member.

A series of hydraulically operable pistons and cylinders are mounted onthe sleeve member 27 above the packing assembly 12. As shown in FIG. 2A,a plurality of partitions 73, 74 and 75 are formed at spaced intervalsalong the sleeve member 27. Each partition has a sleeve piston 17, 18 or19 operatively associated therewith, each sleeve piston having anupwardly extending tubular portion 76, 77 or 78 which is sealed withrespect to a partition by a seal ring 79,80 or 81, as well as aninwardly extending flange portion 82, 83 or 84 which is sealed againstintervening portions of the sleeve member 27 by rings 85 or 86. Eachportion 76, 77 or 78 has one or more slots 88 or 89 cut in the upper endthereof in order to communicate fluid pressure in the well bore abovethe packing assembly 12 with the respective lower surfaces of the sleevepistons 18 and 19. The lower surface of the sleeve piston 17 will alsobe subjected to a lesser fluid pressure than that below the packer viathe medium of the upper packing ring 31. Alternatively, a spacer ringcould be used to permit direct communication to the lower face of thesleeve piston 17, in which case a seal ring would be used to seal theportion 82 against the sleeve member 27. Ports 90, 91 and 92 are formedthrough the wall of the sleeve member 27, eachport serving tocommunicate the pressure of fluids in the flow passageway 28 with theupwardly facing transverse surfaces of the respective sleeve pistons.The fluid passageway 28 is, as previously described, in communicationwith the well bore below the packing assembly 12, so that it will beappreciated that the upwardly facing transverse surfaces of each sleevepiston are subject to fluid pressure in the well bore below the packingassembly.

ln order to provide a force balancing system to prevent fluid pressureinside and below the body member 11 from pumping the valve head 20upwardly and opening the bypass passageway 28, a pressure cylinder 95 ismovably mounted on the body member 11 and has an annular cap portion 96extending inwardly and sealed against the body member by a seal ring 97.A latch sleeve 98 is mounted inside the cylinder 95, the sleeve beinglongitudinally slotted to provide a plurality of circumferentiallyspaced spring fingers 99 extending downwardly and terminating inenlarged head portions 100. The head portions 100 have outer inclinedsurfaces 101 which are engageable with inner inclined surfaces 102 onthe cylinder 95 to force the head portions inwardly in response toupward movement of the cylinder relative to the latch sleeve 98. Anannular enlarged portion 103 of the valve head 20 provides a balancepiston which is sealed against the inner periphery of the cylinder 95 bya seal ring 104. A pressure passage 105 is provided between the valvehead 20 and the i valve seal 29 and enables the pressure to actdownwardly on the upwardly facing transverse surface 106 of the balancepiston 103.. l

A plurality of radially movable lug elements 110 are i movably receivedin openings 111 through the wall of the upper endportion of the sleevemember 27 as shown in FIGS. 2A and 5. The lug elements 110 are movablebetween inner or 1 retracted positions as-shown in FIG 2A, but areexpandable outwardly to extended positions by engagement with anenlargedportion 112 of the valve head 20. The lug elements 110 can bebiased inwardly toward retracted positions byan annular band spring1l3or the like. When the body member 11 is telescoped downwardly withinthe sleeve member 27 during setting of the packer, the pressure cylinder95 and the latch sleeve 98 will descend over the lug elements 110 sothat the enlarged heads 100 on spring fingers 99 are located below thelug elements. The enlarged portion 112 of the valve head 20 a willextend the lug elements 110 to their outer positions to OPERATION Inoperation, the parts can be assembled as shown in the I drawings andattached to the lower end of the pipe string P for .insertion into awell bore. Duringlowering, the drag blocks 15 are forced to slidedownwardly in frictional engagement with the wellcasing wall, andengagement-of the control lug 64 .within the closed end channel 66prevents upward movement of the cage member 14 relative to the bodymember 11, thereby maintaining the slip elements 13 and the expander 16in spaced relationship to prevent expansion of the slips. The packingrings 31 areretracted, and'fluids inthe well bore below the packer canpass upwardlybetween the packing assembly 12 and the well casing wa'll,as well as through the bypass passageway 28 formed between the sleevemember 27 and the body member llvia the expander ports 38 and the Isleeve member ports 37. t

At setting depth, the body member 11 is lifted slightly and 1 thenloweredwhile torquing to the right in order to release the jay-slot 65from the control lug 64 on the cage member 14.

The drag blocks function to hold the cage member 14 stationary so thatthe body member 11 can be moved downwardly relative thereto. When thebody member 11 has been lowered sufficiently, the pressure cylinder 95will telescope over the upper end of the sleeve member 27 and the valve'head 20 will engage the seat .30. When the balance piston 103 comesinto abutting relation with the upper end of the sleeve member 27, thepressure cylinder 95 is in position I to be latched; against upwardmovement as previously described, and the sleeve member can be forceddownwardly by the weight of the pipe'string P to effect setting of theslip elements 13 and the packing assembly 12. Downward move- A meritwill bring the expander cone 35 behind the slip elements 13 so that thecooperating inclined surfaces 39 and 44 will cause outward shifting ofthe 'slip elements until their teeth 43 bite into and grip the wellcasing wall as shown in FIG. 68. Now the expander 16 cannot move anyfurther downwardly,

so that continued thrust on the sleeve member 27 will advance the upperabutment 32 toward the lower abutment 33'and cause the packing rings 31to be compressed and expanded into sealing engagement with the wellcasing wall.

' The initial downward movement of the body member 11 relative to thesleeve member 27 will have positioned the backing surface62 behind thelatch elements 57 to prevent inward movement thereof. Thus, as thesleeve member 27 is driven downwardly by the body member 11 relative tothe slip elements 13 and the cage member 14, the latch elements 57 areforced to ratchet inside the clutch ring 51 which will trap thesleevemember 27 in the lowermost position to which it is moved. The sleevemember 27 cannot move upwardly as long as the backing surface 62 isbehind the latch elements 57 because, as previously described, upwardmovement will only cause the clutch ring threads 59 to more tightlyengage the latch element threads 58.

lnasmuch as there is a considerable extent of longitudinal movementpossible of the body member 11 relative to the sleeve member 27 withoutremoving the backing surface 62 from behind the latch elements .57, thepipe string P can be manipulated at the surface during installation ofthe Christmas tree without disturbing the setting positions of the slipelements 13 and the packing assembly 12. When the well is ready to beput on production, a certain amount of the weight of the pipe string Pcan be imposed on the body member 11 to assist in keeping the valve head20 in closed position, as well as to help prevent any upward movementdue to pressure from below.

The balance piston 103 on the-body member 11 also prevents upwardmovement of the body member due to pressure from below. The fluidpressure in the well bore below the packer is, channeled to the upperface 106 of the balance piston through the ports 38 and 37 and thepassageways 28 and 105. Since the lower surfaces of the balance pistonare subject to fluid pressure in the well bore above the packer (throughthe open lower end of the-locking pressure cylinder and the latch sleeve98), the pressure difference is effective as downward force to counterbalance the upward force on the body member 11 due to greater pressurefrom below.

As fluid pressure in the well bore below the packer 10 is increased, theset conditions of the packing rings 31 and the slip elements 13 arefurther maintained in the following manner. The fluid pressure in thewell bore below the packing assembly '12 is transmitted through thebypass passageway 28 and via the ports 90, 91 and 92 to the upwardlyfacing transverse surfaces of the sleeve pistons 17, 18 and 19, whilethe lesser fluid pressure in the well bore above the packing assembly 12is communicated via the slots 88 and 89 to act on the downwardly facingtransverse surfaces of the sleeve pistons 18 and 19 and via the upperpacking ring 31 to the downwardly T facing surface of the sleeve piston17. The pressure difference provides a downward force on each'sleevepiston, the foreces being additive due to the series relationship of thesleeve pistons. Thus, the greater fluid pressure in the well bore belowthe packing assembly 12 acts in acumulative manner on the sleeve pistonsto provide a downward force to the upper one of the packing rings 31.The force will increase the compression of the packing rings 31, and aportion of the force is also transmitted through the packing assembly 12to the expander 16, forcing the cone 35 in a downward direction torestrain the slip elements 13 in tight gripping engagement with the wellcasing.

The well packer 10 is released from set position by applying a straightupward pull on the pipe string P at the surface. The lost motionavailable between the body member 11 and the pressure cylinder 95 willenable the enlarged portion 112 of the valve head 20 to be removed frombehind the locking lugs so that the lugs can move inwardly andreleasethe latch sleeve 98. As the body member 11 is moved upwardly, the bypasspassageway 28 is opened to equalize pressures, and eventually thebacking surface 62 will be displaced from behind the latch elements 57,enabling inward movement of the latch elements and release of thethreads 58 from the threads 59 on the clutch ring 51. The open endedchannel 68 and the inclined channel of the jay-slot 65 willautomatically guide the control lug 64 back into the closed end channel66 to relay the cage member 14 with respect to the body member 11. Ofcourse, the release of compression force on the packing assembly 12 willpermit the rings 31 to inherently retract, and the sleeve membershoulder 36 will pick up the expander 16 to permit the slip elements 13to retract-Then the packer 10 can be shifted longitudinally in the wellbore.

A new and improved well packer apparatus has been disclosed havingsettable packing and slips and a hydraulic system which responds togreater fluid pressure in the well bore below the packing than above thepacking to retain both the packing and the slip in set positions. Sincecertain changes and modifications will occur to those skilled in the artin view of this disclosure without departing from the inventive conceptsinvolved, it is the aim of the appended claims to cover all such changesand modifications which fall within the true spirit and scope of thepresent invention.

lclaim:

l. A well packer apparatus comprising: a body member movablelongitudinally within a sleeve member that carries settable packingmeans adapted to sealingly engage a well conduit wall; normallyretracted slip means, and expander means movable downwardly relative tosaid slip means for shifting said slip means outwardly into grippingcontact with the well conduit wall; and hydraulic means surrounding aportion of said sleeve member and capable of movement longitudinallyalong said sleeve member and with respect to said body member, saidhydraulic means being coupled to transmit downward force to said packingmeans and via said packing means to said expander means to retain saidpacking means and said slip means in set positions in response togreater fluid pressure in the well bore below said packing means thanabove said packing means.

2. The well packer apparatus of claim 1 wherein said hydraulic meansincludes a plurality of members arranged in series relationship, each ofsaid members having an upwardly facing transverse surface subject to thepressure of fluids in the well bore below said packing means and adownwardly facing resultant transverse surface subject to the pressureof fluids in the well bore above said packing means.

3. The well packer apparatus of claim 2 further including a bypasspassage between said body member and said sleeve member; valve means onsaid body member adapted to close off the upper end of said bypasspassage; and means for preventing said valve means from closing off saidbypass passage during longitudinal movement in a well conduit.

4. The well packer apparatus of claim 3 further including balancingmeans on said body member adapted, when said bypass passage is closed bysaid valve means, for forcing said body member downwardly in response togreater fluid pressure in the well bore below said packing means thanabove said packing means.

5. A well packer apparatus comprising: a body member carrying a packingstructure including a sleeve member and packing means on said sleevemember adapted to sealingly engage a well conduit wall; slip means andexpander means movable downwardly relative to said slip means forexpanding said slip means into gripping contact with a well conduitwall; hydraulic means coupled to packing means and responsive to greaterfluid pressure in the well bore below said packing means than above saidpacking means for forcing said packing means and said expander meansdownwardly to retain said slip means in expanded positions; andreleasable means for locking said slip means in expanded positions whileenabling longitudinal movement of said body member relative to saidsleeve member.

6. The apparatus of claim 5 wherein said releasable means includeslaterally movable first gripping means on said sleeve member, secondgripping means associated with said slip means and engageable with saidfirst gripping means and a 8. The apparatus of claim 7 further includingpassage means for feeding fluid pressure in said passageway to saidhydraulic means.

9. The apparatus of claim 5 wherein said hydraulic means includes atleast one piston and cylinder means coupled in force transmittingrelationship to said packing means. 7

10. The apparatus of claim 9 wherein said piston and cylinder means isprovided with an upwardly facing transverse surface subject to fluidpressure in the well bore below said packing means, and a downwardlyfacing resultant transverse surface subject to fluid pressure in thewell bore above said packing means.

11. The apparatus of claim 5 wherein said hydraulic means includes aplurality of piston and cylinder combinations which are coupled inseries relationship to each other and in force transmitting relationshipto said packing means.

12. The apparatus of claim 11 where in each of said piston and cylindercombinations is provided with an upwardly facing transverse surfacesubject to fluid pressure in the well bore below said packing means, anda downwardly facing resultant transverse surface which is subject tofluid pressure in the well bore above said packing means.

13. A well packer apparatus comprising: a body member adapted forconnection to the lower end of a pipe string extending upwardly to thetop of a well bore; a sleeve member mounted on said body member andlaterally spaced therefrom to provide an annular fluid bypass passagetherebetween that is open to the well bore at the upper end of saidsleeve member; valve means on said body member and sleeve member forselectively closing off the upper end of said bypass passage; normallyretracted packing means on said sleeve member adapted to be expandedoutwardly into sealing engagement with a well conduit wall; normallyretracted slip means and expander means below said packing means, saidexpander means being movable downwardly relative to said slip means forexpanding said slip means outwardly into gripping engagement with a wellconduit wall; drag means coupled to said slip means to enable relativemovement; means responsive to downward movement of said sleeve member bysaid body member for expanding said packing means and said slip means;releasable means including coengageable latch elements on said sleevemember and said drag means for retaining said packing means and saidslip means-in expanded positions; and means on said body member forlocking said latch elements in engaged relation during upward anddownward movement of said body member relative to said sleeve member.

14. The well packer apparatus of Claim 13 further including hydraulicmeans above said packing means and responsive to greater fluid pressurein the well bore below said packing means than above said packing meansfor exerting downward force on said packing means and through saidpacking means to said expander means to restrain said packing means andsaid slip means in expanded positions.

1. A well packer apparatus comprising: a body member movablelongitudinally within a sleeve member that carries settable packingmeans adapted to sealingly engage a well conduit wall; normallyretracted slip means, and expander means movable downwardly relative tosaid slip means for shifting said slip means outwardly into grippingcontact with the well conduit wall; and hydraulic means surrounding aportion of said sleeve member and capable of movement lonGitudinallyalong said sleeve member and with respect to said body member, saidhydraulic means being coupled to transmit downward force to said packingmeans and via said packing means to said expander means to retain saidpacking means and said slip means in set positions in response togreater fluid pressure in the well bore below said packing means thanabove said packing means.
 2. The well packer apparatus of claim 1wherein said hydraulic means includes a plurality of members arranged inseries relationship, each of said members having an upwardly facingtransverse surface subject to the pressure of fluids in the well borebelow said packing means and a downwardly facing resultant transversesurface subject to the pressure of fluids in the well bore above saidpacking means.
 3. The well packer apparatus of claim 2 further includinga bypass passage between said body member and said sleeve member; valvemeans on said body member adapted to close off the upper end of saidbypass passage; and means for preventing said valve means from closingoff said bypass passage during longitudinal movement in a well conduit.4. The well packer apparatus of claim 3 further including balancingmeans on said body member adapted, when said bypass passage is closed bysaid valve means, for forcing said body member downwardly in response togreater fluid pressure in the well bore below said packing means thanabove said packing means.
 5. A well packer apparatus comprising: a bodymember carrying a packing structure including a sleeve member andpacking means on said sleeve member adapted to sealingly engage a wellconduit wall; slip means and expander means movable downwardly relativeto said slip means for expanding said slip means into gripping contactwith a well conduit wall; hydraulic means coupled to packing means andresponsive to greater fluid pressure in the well bore below said packingmeans than above said packing means for forcing said packing means andsaid expander means downwardly to retain said slip means in expandedpositions; and releasable means for locking said slip means in expandedpositions while enabling longitudinal movement of said body memberrelative to said sleeve member.
 6. The apparatus of claim 5 wherein saidreleasable means includes laterally movable first gripping means on saidsleeve member, second gripping means associated with said slip means andengageable with said first gripping means and a locking surface on saidbody member for holding said gripping means in engagement with eachother to prevent relative movement between said sleeve member and saidslip means.
 7. The apparatus of claim 5 further including a fluidpassageway between said sleeve member and said body member which can beopened to the well bore above and below said packing means; and valvemeans on said body member for selectively closing off said passagewayfrom communication with the well bore above said packing means.
 8. Theapparatus of claim 7 further including passage means for feeding fluidpressure in said passageway to said hydraulic means.
 9. The apparatus ofclaim 5 wherein said hydraulic means includes at least one piston andcylinder means coupled in force transmitting relationship to saidpacking means.
 10. The apparatus of claim 9 wherein said piston andcylinder means is provided with an upwardly facing transverse surfacesubject to fluid pressure in the well bore below said packing means, anda downwardly facing resultant transverse surface subject to fluidpressure in the well bore above said packing means.
 11. The apparatus ofclaim 5 wherein said hydraulic means includes a plurality of piston andcylinder combinations which are coupled in series relationship to eachother and in force transmitting relationship to said packing means. 12.The apparatus of claim 11 where in each of said piston and cylindercombinations is provided with an upwardly facing transverse surfacesubject to fluid pressure in the well bore below said paCking means, anda downwardly facing resultant transverse surface which is subject tofluid pressure in the well bore above said packing means.
 13. A wellpacker apparatus comprising: a body member adapted for connection to thelower end of a pipe string extending upwardly to the top of a well bore;a sleeve member mounted on said body member and laterally spacedtherefrom to provide an annular fluid bypass passage therebetween thatis open to the well bore at the upper end of said sleeve member; valvemeans on said body member and sleeve member for selectively closing offthe upper end of said bypass passage; normally retracted packing meanson said sleeve member adapted to be expanded outwardly into sealingengagement with a well conduit wall; normally retracted slip means andexpander means below said packing means, said expander means beingmovable downwardly relative to said slip means for expanding said slipmeans outwardly into gripping engagement with a well conduit wall; dragmeans coupled to said slip means to enable relative movement; meansresponsive to downward movement of said sleeve member by said bodymember for expanding said packing means and said slip means; releasablemeans including coengageable latch elements on said sleeve member andsaid drag means for retaining said packing means and said slip means inexpanded positions; and means on said body member for locking said latchelements in engaged relation during upward and downward movement of saidbody member relative to said sleeve member.
 14. The well packerapparatus of Claim 13 further including hydraulic means above saidpacking means and responsive to greater fluid pressure in the well borebelow said packing means than above said packing means for exertingdownward force on said packing means and through said packing means tosaid expander means to restrain said packing means and said slip meansin expanded positions.